The Company has certain assets and liabilities that are measured at fair value on a recurring basis according to a fair value hierarchy that prioritizes the inputs, assumptions and valuation techniques used to measure fair value. The three levels of the fair value hierarchy are:

Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities.

Level 2—Quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly.

Level 3—Inputs are generally unobservable and reflect management’s estimates of assumptions that market participants would use in pricing the asset or liability. The fair values are determined using model-based techniques, including probability-based simulation methodologies.

The determination of a financial instrument’s level within the fair value hierarchy is based on an assessment of the lowest level of any input that is significant to the fair value measurement. The Company considers observable data to be market data, which is readily available, regularly distributed or updated, reliable and verifiable, not proprietary, and provided by independent sources that are actively involved in the relevant market.

The following tables reflect the Company’s financial asset balances measured at fair value on a recurring basis (in thousands):


	March 31, 2024
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	30	$	—	$	—		$	30
Commercial paper	2		43,858		—		(22	)		43,836
Total cash equivalents		$	43,888	$	—	$	(22	)	$	43,866
Short-term investments:
Commercial paper	2		9,451		—		(5	)		9,446
U.S. government debt and agency securities	2		34,931		—		(110	)		34,821
Total short-term investments		$	44,382	$	—	$	(115	)	$	44,267


	December 31, 2023
	Level	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market fund	1	$	63	$	—	$	—		$	63
Commercial paper	2		59,227		—		(30	)		59,197
Total cash equivalents		$	59,290	$	—	$	(30	)	$	59,260
Short-term investments:
Commercial paper	2		6,431		—		(4	)		6,427
U.S. government debt and agency securities	2		50,723		—		(315	)		50,408
Total short-term investments		$	57,154	$	—	$	(319	)	$	56,835

All the commercial paper, U.S. government debt and agency securities, U.S. treasury bills, and corporate bonds designated as short-term investments have an effective maturity date that is equal to or less than one year from the respective balance sheet date.

As of March 31, 2024, the Company does not intend to sell any securities in unrealized loss positions, and it is not more-likely-than-not that the Company will be required to sell such securities prior to the recovery of the amortized cost basis. Based on the Company's assessment, the Company concluded all impairments as of March 31, 2024 to be due to factors other than credit loss, such as changes in interest rates. A credit loss allowance was not recognized and the unrealized losses for available-for-sale securities were recorded in other comprehensive loss.